PARASITES OF THE LUNGS OF THE SHEEP.

Otago Witness, Issue 2572, 1 July 1903, Page 6

PARASITES OF THE LUNGS OF THE SHEEP.

THE EED THREAD "WORM (STEOXGy-

JAJti RUFESOENS) AND THE iLVIR

WORM (PSEUDALUS OVIS)

It ia a remarkable foot iv tlio hisiory of the rod hair woiin that it ie chiefly known by the prccenoe of its embryos in the Jivngs. To a number of writers on tha hibtory of

parasitic worms the creature must have bc-en mo-re or less a myth, as in lhe:r descriptions they speak of it variously as being, on the one 'hand, a few millimetres long, rind on ths ofcher as r-eachimg the length of six inches. Tory mveh in the same wRy the embryos, which are found in abundance in the lunga of sheep^ the bronchial tubes of which are infested with the white thread worm, have been desc-ibcd over and over again as embryos of that worm. Tho description 'giv&n fey Alois Koch in his work on the thread worms^of the sheep's lung is worth motice, a-3 it co-nveys his own impressions on his fir«t dliscovcay of the red hair worm in a (specimen of luugs sent to him by a profetsional friend. In addition to tbe white thread worm, which he found, he suddenly came upon some eoiled-up threadworms -of a uniform dee-p reddish-brown colour. These worms w r ere remarkable, "he fays, on account of their colour and their oxTremoly at;«inuatcd bodies. Tlieie w-ere only about 20 Fpecimc-n'S, and, fo far as he could judge, the Tyorm was about 20mm, or xn*her o\er threeqitarteTS of an inch, in length, l>ut oil account of tlie extreme friability of the body he was not successful in obtaining a tingle perfect tpecinieu out of the few at his disposal. At this point it will be convenient to bre>ak off in order to give a description of the other lung worm of the t=h<?ep, the hail worm, for reasons which will presently appear.

A mere cursory inspection of the lungs of a sheep will vc-ry cfton reveal tbe pressncs of a large number of oircular 'red fpota. ftb-wt an edghth of an dnoh in diameter, interspersed with small tuberelelike m'aesos, which are slightly elr-vated abo'*e. the furfacs, r-atliT hard to the touch, and sometimes ealoaj-e.onis. If a portico of lung so moi'iied bo taken, nnd oue of the Tod spots be pricked with a netd'e, and the pleura -elevated from it, there will be. seen a Email dark, hrowu ma^s, which, on 'bci.>s liftPd out by the pcint of the needle and ■placed on a glass tilde- with a drop of water, -will begin to uncoil itself, and dually reveal itself as the hair worm.

To return now to the point at which Alois Kooh had airived in hi- de=ci'iption of tbe Ted 'hair worm, it is worthy of remark that he -expresses his gTcat astoninlim-ent tlva-t th°. embrj-oa which he found in the bronchial tubes, in Which ths few specimen* of the red ihair parasite- wP.re, exaoUy rrG=mbl''d those wLjch lte bad pre-vi-ouoly-desfn-ibpd j,isd illuetratsd as belcciguig to tlie hair worm. The circumstance, he say<s, toother with tlie similariig' in the sfcructmc- of the worm and the Size of tbe •egg-, led him to .suppcv that he had to dr.al wirh the hair Jung wo;m in -a state of rr.r.tamornho-ip — in oilier worJ?. that the hair lung worm "was one stage of the Tt>d hair woirn. Tl^t+ the two worms ■have TiDon oonfonndod cannot be for a uioramt quf-ticn-Dd. The worm which is found in the numcrotis red fpofs amd tub'Tolr-liko nodalc 1" t' e hines. and v.liiclj \w*\ bet >i cV s-ds -d' l ir><^d as the huiih.ncr vorm, :«• r^T found in jiwv-iatjou v. it,h -c^gs <"n.l err.'-rw-. Nor Jire any ■refg^ socn in the- wo»m it-.e'f. md wh-ei'wer the l.aii lu^g wo pi h f"" £ rribcd in '-oni 11 ' ration vriili and embryos it ;■> fjiutr s-af"o to porrlud" tliat the rr-d lung worTn \\z& bc'&n mistaken frr tl:-** haii lung worm Tb n worm wJ'iih i« d« scribed bj- *OTr.f* wri'-»r« :■(* th« Te '. \w\-J vvoiTn. md 9.? .1 fiara-iie of f^oire 7m 101/5, it, dearly a try't K-aJ r>rcature v. Lmj!i ha' ih-vm- bern really ri.'fii in life lun?« of biie. <-hr'p.

Hcrr J\o<'h co-»; csi to :,priik 'if t!-<* ice'htiiv of ilia 1-<»<l luriir worm \\ uli the li,iir king wrrvn pLludinH iv tlie. fin-t p'l^-- to the difficulty wl.ic-li he OD'-cuntercd in the fart of the body of ilie red Jung worm b"uacr three cr four trm r s tli« tli«ctr:PF c of that of the liair lun<? werra: but lie qfts over tins by <rusprf k =tin!r Hbs*- th" red lujik worm is Tverpo- f inl!y- advrrK mjr into the -fir.^t capilkry tubes of the brenchu and by fch-is «!uc-«zmg finally reisrxlves itf^lT into the mrrr© slender store oT the hair lung worm. H> eives 11 lcno miuut-e de-pcip-t:o.i of the anatomy of both worms, and cndruvours to show how certain structural di-fiorencp--? may fcc-ooino modified .«n as to 1 : "rosfih cr>(\ othpr until they bceom-a i''t*i^ol. at>d It fiuUbes by rffcring the qti-^lion, '"What is tlie red lung worm?"

To thid lie rep'ics that >the worm is the. hair huig worm iv a bUm& of metamorphosis, or ratht-r that t-lie hair lung worm is a Jietamorfhoied and duiuiii^hed red lung worm W:th regard to this -eoritention it may be c'o3:ivcd fehat the investigations whioli havebowi made by Profcr.sor H. T. Brown, C.8., lead him fco* conclude th>it Alois Koch is probably correct in the view that the- two worm? are, if not identical, at least closely rc-lat-e-cl ; but tho faots whirih he lias observed do not accowl precisely w;th Koch's etat-e-ment as to the tize of the two worms. In aM the i>peciHK»n» Professor Brown ias mot with— -and tl'.ey hn;e bc«.n exceedingly nujiicrouf — the- hair 'king -worm. h?s pie-scntc-d the of a tliiclt-cr worm than the red lung worm, and assuming that the two worms arc rr.ally identical —a point which Herr Koch admits to bu only eupporfced on the uuo&rtain basis of a buppoaiti oa2 — it would sewn to bs more 111 accorKlcuce w.th the facts to eoiiMu.er that il>e hair luiif; worm 1= ths last stage of tin* rod lung worm, rather than ilis- fiitt; in sliort, fehat ha\iag finished its life's woik and doa© as nmch damage to t>he lung etruerures as the- ci'fumstanoes c-f ite organi?ation pei-mit, it finally retires inte am isolated position in various parts of tire lungs, ■especially on thp eiH-faoe. coils itself op, said at length becomes a mere calcareous mfi" 1 -.

Eff*ct= of Ils3 prcsenod of the led lung worm in the hufcg-: —

It is more than probalbls that fclie stockowner will nat "fe?l very much interest iv the. possible solution of fill© problem as to the exact position of the rod lung -worm in natural hk-tcry. It v.il!, however, conoc-rn him very imjoh to know that the. worm cornmil)? terrible havoc -when it gets into the ltoag ia laTge numbers, arid that in small n-iußLbcw it is almost a censtaut inhabitant of every shic-op-keopiag country, and piobab'y wherever shee<p are to be found. Tlie mature worm, it has been already pxpiained, is easily overlooked; indeed, it is vr.ry difficult lo' obtain a j.;erfc-ofc specimei). Thj embryos, however, and tbe eggs, with porticus of th& a'lult worm, can be found withtmt trouble-, Init oni?' by tho aid <of the micrOK>ope. On examining fehe limgs of a alMjep from a few months old, it is usual to observe- on fcho borders of the lungs, -cad according to frhf extent of the invasion, more •or Ices distriljute'd through the structure of the organ, gieyiih white or jsCkm<Ctt.in>es dull Ted nodules varying in alze from a pea to a liazcl nut. In .somf> ad\anoed ca^cs which were- under observation in a flock in the Soutli of Fnigiand, tlip greater part of both lun^s of the afFerted oheop had b?cn oonvprtod into a white fibrous mp=>s, scattered through winch wrro nodules containing thousand* of -embryos »md numerous v.atur" worm?. In the majority of tho modules of all fcize.= the o&ntro was by a xn all mass of gr&enia'.i -yellow iia^ty 01 cheesy *übstrroe, in wlin h tJie ogga aud embryos were abundant. Tae adult ivorms, nowevor, appivrently prefer a position on tho outer part -of and away frenn this gT&e« substance, Sprah-alHy 'b?^a!;'99 they li?vo «i>!ro.vJy ez-ihaifc-.fc(vl whab^vtr nutritive material the mass may hnve coisUunwL

It will b» »p.pa.Tf-nt from the above obscrvadJiCßS^bat tlie eßr&bs of the red rang worm on the lung st-rnciures vary from osmpapatively ins.puificant ohaiig-es, as the *■&- eiilt -of the irmaitum which they ■cause, to actual 01/litfira'.'ion of a greater part of the normal f-rriiomua and the su'hstitution of fibrous lifl.ut' in its place. It would be (■•vpecU'd that such extensive oluingcs would ba f;ii-t\ and in th". 03 so which lias just be^n r<»f-Ti>e>d to, in v.'hiiAi a inrge irambar of tlboep suffered from this fibrous degeneration •of tite Iu r igw, the les^e were very ••oiisid-eT-able. Mid tlie rrumaU which larhally re-oovorc-d Tei»;ur.'>d in an -c-mnc a>ttc\ roudition.

("hie <-!r©nmi-'ta i nce wl'ich rendtT tho rvd limp: worm a inor^ objectionable -w.-itiT.t tlia^n tlio ordinary white thread "wurm i*> tli« pormw-noy of itu •cxistßr.c?. WhefrJier the m-vp'W'* are frw cr many in number, atid ronfi:,« tlstrnf-lv-c* to tl» borders of th-e lunjr or f-prciul ov.t tl's greater part of it, thty »t?"2fn to ocrncv thomsHTes in feeding on tke matTtal whioh is at iiand and -deporitniar ciggs, wluoh are subsequently l.iitrlicd. a large imni'jar of embryos bain?' <"'l fr r >°, and < iueing piorfirive irritation by liic.ir mo-3«anfc mo-vent.- iaie. It would aprear to be fche ease 4'kat nothing short- of th~ pro : =urp winch i? .exerte-d liy the steadilyii!creasing density of the fibrous deposit has "tire- effect of destroying the brood. This pr.r> o pM. -which is pomparafcivelv harmil-wa' ■n li^n thr worms -are few in number, is fatal ta thtj oheeip -inhoii fcho -para^i'tOß .have invacli»d aveoxly tbo whole of tho lung *tractui'P.

Profe==or Brown — to -whose investigations an 1 \vi\it"mg3 we? are -rn-deljted for' these art'dos on parasites affeet»n£ ulieep — suggr=ts tliat flodcmasfcars must to ■urg'&d to understand that the conditions of the cheep's existence are less favourable to them than tc J*e parasjtPß whioh destroy them. It is -ps-rfcefch" T*ell known th«t the rnfeefced ai'ioittils themselves provide the means for

the continuanea of the parasites which feed on them. A few «feeep twn+a- ; ining in their hing3 tho worms which have bean described, even though they might not themselves give any cvidance ol suffering from tib-eim, would contribute to a considerable extent to the contamination of the lands on which ilioy fed. Wl'.en ths fe-w becom* tnacredsj the misolief is n^osssrtriZy icereseed in proportion. Overcrowding is unqueatioEflbJy one earso, axH an important one, ol th& eon)?.m'nat3on of 6heep lands, aixd ccnsi-aisilv , feeding on the same- grounds- is artofher. Another indirect oauro of disease is the es- , posure to extreme olimat-ie ciranges, ar-d another is tlie one. winch :s constartly ih.o s>ubj"ot of complaint by th-e fariDcr Ldmsslf — his .«hort supply of food. Exposure and de-f.;i'i-cy of food necessarily induce debility cf tho Gystsm of the sheep, and in this state they become prifectly cacy victims to the parasites which infest them. Again, if may be safoly affirmed ol every pcirtura <m wliidi ' p-.rasir-ej: aro abundantly preseiit thiattl* circv.mptaEc^s are favourable to their existence ; in other wtsrds, that thei* is a redunJarncy of moisture in th-e soil or in prvk il< e-s. StagTiasit pcola, ur even small. scJaic^ly-n&tJiitable 1 addles, may liarl>oui-myi-iac's of tJve ge«R= of fwu-adtes ready to tike up their roidcnce in tbe waim-blooded anima'. TREATiIFJN'T OF PARA.SITTC LUXG

DLSKASE OV THE SBEKP

It must be> obvious bbat very httle will bo gained' by limiting preventive ot curative measures to the dUctofd animals, while the cuirees cf the <lisea€£, both direct and contubulGry, are allowed to flourish undisturbed. ' Tne trcateient of parasitic lung disease, in the sheep will therefore com© under two div.sionsj oue which is steic*ly witlun tke province of the veterinary surgeon, and the. other entirely the business of tho farmer.

Tak-ng tl c veterinary division £rst, as bi ing the oue whklh is directly concerned witli the tine of the disease, it may be pciit-d out, in the •first; place, that there is \oiy little encoui-pgement for the v-ereri-naiy practitioner to dc.ote himself ito tbe tnatmeut of this olass of dieeasa. in auimaiu of liie farm ; and the mo3t he is commoHilj expected to do as to supply the fiockmaster with a mixture, to be given in certain dose-3, with the view of destroying the worms, which is tantamount to .saying that nothing in the way of^curative tuatment is attempted until the diset-se is so well established that anyone can dekct it. As a rale nothing at all is done until tho worms have taken up a strong pssition, from which experience proves it is not vary eas=y to dislodge thorn by \h& use of £b& ordinary remedies, such 11s turpentine, crcofote, campliorated spirit, fumigat-ons with tar, carbolic acid, or sulphur, or by injections into the windpipe of carbolic acid, creofote, and (h'oroform mixed with -oil. In this latter n i thed, which has been successful iv many c-50-,, t!ic slrill cf tl>e professional man is absolutely n'ccssary. It is by no means aa cat.-/ task to punciuxe t"bo wi-ndpipe with a fine ncedic-pointed syiiiige and inject the proper quantity of material. At the pame time, a pretender may go through the per{ol mance with apparent success by f imply passing the needle thiona'h the slna without entering tbe windpipe at all. The objection to this plan of treatment is mainly that, when a large number of animals have to Its treated, considerable £ii»e is necessarily x«cupietl; indeed, a skilled operator will hardly manage with lass than five minute* for each aivma]. At anyrate, if Tro could successfully inic-et 20 in the course of an hour he would have, done very good work indeed. Frofc?sbr Brown makes this statement as a matter of experience. It is also made with a knowOedge of tlie fact that a mere plunge of the syringe through tlie skin and tho mice lion of tho medicine anywhere but into the windpipe would not occupy more than a minute, and, of course, had better not be done at all. The flockmaster. therefore, who elects to adopt this plan of ti eat in;* liis she-sp must incur the ccst of employing 1 -a skilled operator.

In lvference to the red fcrng worsn, Professor Biown finds it necessary to state at once that injection into ftp windpipe, or indeed any other form of treatment, may be looked upon as nearly hopeless. Tlie ■embryos of the worm have been found alive and pc-rfnetly actave in Bueap whidh have been treated with a course of arsenic, sulphate of n'ou. and turpentine, tbe treatment being carried -over several weeJcs, and the subjects of it being at last killed by tbe iiycotion of proifsie acid. They have also b n en found alive in a portion of lung ■which had boon kept, for several hours, in a slroncf solution of eoirosive sublimate. After this experience, therefore, it wmild "be absurd to sugpest that auy drug which cou'.d be introduced would kill these worms, even if it killed the sheep.

Undei the 6eeond hr-adinf — thai of the agricultural a*poot of the treatment —^ProJpgoor Brown doe-3 not venture to sny nrarih, as, in addition tn reasons already given, J.l>ero is, he paj-.s, tlie further reason that he does not know hew flockraasbers are to- find few feeding crrounds dar their snh-efip in order to avoid those they know to be info=ttHl with th°. rmbryos cf parasites. He f.'rga;e-.t.s, liowrvor, that top-drpssincfl of lime 3r Fnlt JLt )«ror>er tinies applied to in-fp.-ted pßiihirfs. efficient dTainacre and rnilincr of stagnant pack, shelter ■during inclement weather, and tiic practice of pivinff the sheep in the early morninir a good meal of (fry and nroperly salted food befnro they f?Ji upon tlio dangerous prrouiid would effect Dun-" thing in iiVi-p- v.ay of p>e\p»tion. The problem which lias to b? folded has r<"frrerc -to tJrprorcr'fm rather tlian euro, which so far as the Inner worms nrp oencernrd. the rod lunp. worm p=Tif>fia!ly, rnnnofc bo undert-ilen witli much liopc of success. Prevention, luiwevpr. is more promLsintr.

Tt is m (nip as f\vr it ■was that certain plia^m of (he lif^ I'is.tory af thread worms nro stiil oli-cifo Tliis want of knowledge, liowo\or, d<-os not constitute a very serious objfftion api'iist the adoption of preventive measure*. There is sufficient piidenre to snt'sfy anyone that the -embryo* of the worms ar« nartfred frwlv over the fepflincr trrour.df. and whotlior tliev pas* through an -intei mediate host or not, they Sf>m.j>l»oiv acquire a sufficient development to enable thorn to take up iTieir .refidence in fie nSopp which feed on the infested eroundi?. Til" 1 best hope of success must rf«t on the «"•% of means to intercept the youn" wnrms before thov can effect an imtrn-noe "into f 1 "*. body of bhc intentlsd host. The farmer's aim indowl, shoul3 l>e to treat tliese invisibln enemies as lie would if he could ses them in their i&onsauife -ereepTrrr -aTjout tlip- oasturpa as he walked over his iarm, - Wlien fhe warms fcarre once -taVen -up their T)opition on© essontiai! thinpr which can h? done, without upplpctinir -roedioal Irentment, w to support tV.e Bystcm ot tlie ia-

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fested -animals so as to enable them to r** si-=t the ertccts cf the invasion.